The present invention relates generally to dissipation of heat generated by electronic components, and more particularly to an apparatus for cooling an integrated circuit device.
Cooling of certain integrated circuit devices is necessary to ensure their proper operation and useful life. Also, cooling provides for enhanced performance of such integrated circuit devices.
Various designs for apparatus which cool integrated circuit devices have been developed. Such devices include mechanisms which circulate coolants such as air, water and fluorocarbons through the housings in which they are contained.
One example of such a design is U.S. Pat. No. 4,572,286 which discloses a boiling cooling apparatus that includes a heat generating device which is completely immersed in a liquid coolant which partially fills a sealed container. At least one vertically extending passage is provided through the heat producing device whereby ascending bubbles formed in the passage by the heat transfer from the heat generating device to the liquid medium cause an upward current flow through the passage. A plurality of current flow control plates are provided for diverting the upward flow of liquid coolant laterally and downwardly along the sides of the container to provide convection cooling and directing the downward flow of the liquid coolant into the lower end of the passage in the heat generating device to provide a cyclic flow of the cooling liquid.
Another example is U.S. Pat. No. 4,698,728 which describes a liquid cooling system that includes a frame holding a plurality of printed circuit boards, each of which has electrical components attached thereto. The system further includes a top reservoir for holding a liquid at atmospheric pressure, a conduit for conveying the liquid in a downward direction from the top reservoir over the components, a bottom reservoir for receiving the liquid plus any air due to leaks from the conduit, a pump for sucking the liquid and air through the conduit at subatmospheric pressures and for returning the liquid to the top reservoir.
Yet another example is U.S. Pat. No. 5,216,580 which discloses an optimized integral heat pipe and electronic circuit module arrangement. A ceramic multi-chip module bearing electronic circuit components has applied to the side opposite the electronic circuit components preparatory metallization and a thermal wick. A heat pipe evaporator chamber and condenser assembly is attached to the multi-chip module and wick assembly. A suitable working fluid is introduced into the vapor chamber and the vapor chamber hermetically sealed. Application of the thermal wick to the heat producing multi-chip module eliminates the thermal impedance contributed by the thermal transmission media, permitting a doubling of heat flux from the multi-chip module to the heat pipe evaporator.
Some prior art devices may allow areas of the liquid coolant contained in the cooling device housing to stagnate thereby reducing the effectiveness of the heat transfer process. This is especially true for passive devices that cool integrated circuit chips (i.e. devices which do not utilize an electric pump or motor to circulate the coolant through the housing). Also, some prior art devices are relatively inefficient at transferring heat away from the integrated circuit device due to their overall configuration and design.
It would be desirable to provide an apparatus for cooling an integrated circuit device that is passive (i.e. no electric pump or motor) and which does not allow significant stagnation of the liquid coolant in the cooling device housing. It would also be desirable to provide an apparatus for cooling an integrated circuit device that efficiently transfers heat away from the integrated circuit device. It would further be desirable if such cooling apparatus was easy to assemble and inexpensive to manufacture.